Apparatus for manufacturing coil members for cores of dynamo electric machines by bending

ABSTRACT

Apparatuses and method for manufacturing coil members ( 230, 250 ) for insertion in slots of a core of an electric dynamo machine, wherein the coil members ( 230, 250 ) are formed by bending portions of an electric conductor ( 10 ). Portions of conductor of a predetermined length are fed through an aperture ( 80 ), where at least one engagement member ( 51 ) can move to engage and bend the conductor ( 10 ) so as to form the configuration of the coil member ( 230, 250 ).

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/118,171, filed Nov. 15, 2013, which in turn is a 35 U.S.C. §371 national stage entry of PCT/EP2012/002055, which has aninternational filing date of May 14, 2012, which claims priority toItalian Patent Application Serial No. TO2011A000435, filed May 16, 2011.The present application incorporates herein by reference the disclosuresof each of the above-referenced applications in their entireties.

BACKGROUND OF THE INVENTION

The present invention relates to apparatuses and processes adapted toproduce coil members having a fork-like shape, or different shapes, bybending at least one electric conductor.

Once formed, said coil members are inserted into slots of a core of andynamo electric machine. Fork-shaped coil members are commonly called“hairpins” in the industry. Other shapes may have an undulatedconfiguration, as described in European publication EP1372242.

The magnetic core in which the coil members are inserted may be, forexample, a stator for an electric motor or for an electric generator.

The hairpin normally has two straight legs connected together by abridge-like transversal part. As a whole, the hairpin somewhat lookslike an upside-down “U”, with the bridge having a cusp-like shape. Eachleg has one free end for inserting the hairpin into the slots of thecore. The insertion into the slots is done by passing the free ends ofthe legs through the longitudinal entrances of the slots and by slidingthem past the opposite side of the core, until the legs protrudeoutwards to a certain extent.

According to the prior art, the hairpin is produced from a conductorhaving a rectangular or circular cross-section. More in detail, theconductor is cut into straight segments of a predetermined length; eachstraight segment is bent around a mould to take a temporary “U”configuration.

The temporarily formed legs are then inserted into the slots of twoconcentric rings, which can rotate relative to each other in oppositedirections. With the legs inserted in the rings, a rotation in theopposite direction will subject the hairpin to a definitive deformation,thus giving the hairpin its final configuration, i.e. with the legsspread apart by the pitch required for inserting them into the coreslots and with the head deformed accordingly.

In a hairpin production process of common use, after being cut, thestraight segment is bent around a first mould to obtain an intermediatehairpin configuration in a plane. The head of the intermediateconfiguration is then pressed against a second mould to obtain thedefinitive configuration, wherein the legs are in the correct positionsfor insertion in the slots. Therefore, this is a process that requiresdeforming the conductor by pressing it onto suitable moulds.

The apparatuses of common use in the art operate automatically and arenot easily adaptable for changes in the geometry of the coil members.

Furthermore, the automatic operations involve pressing the conductoragainst moulds, and this often places high stresses on the conductor andon the insulation thereof, leading to a high risk of damaging thelatter.

OBJECT OF THE INVENTION

It is therefore one object of the invention to manufacture coil memberswhile minimizing the risk that the conductor gets damaged.

It is another object of the invention to produce coil members by using asimplified solution.

It is a further object of the invention to manufacture coil memberswhose configuration can be changed by means of a programmable solution.

It is yet another object of the invention to manufacture coil membershaving precisely bent portions, so as to optimize the placement thereofinto the spaces available in the cores of dynamo electric machines.

Said objects are achieved by the present invention through an apparatusand a method for manufacturing a coil member to be inserted into theslots of a core of an electric dynamo machine.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of the invention will becomeapparent from the following detailed description, which is only providedby way of non-limiting example, with reference to the annexed drawings,wherein:

FIG. 1 is a general elevation and schematic view of the apparatusaccording to the principles of the invention,

FIG. 1a shows a detail of a substitutive unit applicable to the solutionshown in FIG. 1,

FIG. 2 is a perspective view of one type of coil member manufactured byusing the principles of the invention,

FIG. 2a is a view along the direction 2 a of FIG. 2,

FIG. 3 is a perspective view along the direction 3 of FIG. 1,

FIG. 4 is a schematic view along the directions 4-4 of FIG. 1,

FIG. 5 is a schematic sectional view including a part which is a viewalong the directions 5-5 of FIG. 4 and a second part which is a viewalong the directions 5′-5′ of FIG. 4,

FIG. 6 is a view along the direction 6 of FIG. 5, with a partiallysectioned part.

FIG. 7 is a view of a further coil member shape along the direction 7 ofFIG. 2,

FIG. 8 is a view similar to the view of FIG. 6,

FIG. 8a is a view along the direction 8 a of FIG. 8,

FIG. 9 is a view similar to the view of FIG. 8,

FIG. 9a is a view along the direction 9 a of FIG. 9,

FIG. 10 is a view along the direction 10 of FIG. 6,

FIG. 10a is a view along the direction 10 a of FIG. 10,

FIG. 11 is a view similar to the view of FIG. 8,

FIG. 11a is a view along the direction 11 a of FIG. 11,

FIG. 12 is a view similar to the view of FIG. 8,

FIG. 12a is a view along the direction 12 a of FIG. 12,

FIG. 13 is a view similar to the view of FIG. 8,

FIG. 13a is a view along the direction 13 a of FIG. 13.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, there is shown the general sequence formanufacturing coil members according to the principles of the invention.

The unit 11 unwinds the conductor 10 from a conductor magazine 11′,whereon the conductor was previously wound to form a reserve coil.

The cross-section of the conductor 10 in the magazine 11 may becircular, and unwinding takes place by aligning the longitudinal axis ofthe conductor 10 with the axis 100′ of a feeding path.

The path may be straight, i.e. parallel to the axis 100′, with a feedingdirection 10′, as shown in FIG. 1.

The motion of the conductor 10 along the path, and therefore the feedingof the conductor 10 along the path, may occur through a push/pull actionexerted onto the conductor in the unit 16, where motorized belts 16 aand 16 b press against the conductor in the feeding direction 10, asshown in FIG. 1a . Belts 16 a and 16 b are able to apply the push/pullaction in the feeding direction 10 due to the friction existing betweenthe belts and the conductor.

The unit 13 carries out the transformation of the conductor'scross-section, e.g. from a circular cross-section to a rectangularcross-section (or another cross-section with plane sides).

Upstream of the station 13 there is a station 12 for straightening theconductor 10, where the conductor is forced to slide along the feedingpath 100′.

In the station 12, the conductor 10 slides through idle rollers 12′,whose surfaces engage the conductor to force it to follow the feedingpath.

More in detail, while passing through the rollers 12′ the conductor 10engages those surfaces of the rollers 12′ which are arranged laterallyand tangential with respect to the feeding path, as shown in theelevation view of FIG. 1. Therefore, the conductor 10 is bent to followthe feeding path.

In the unit 13 there are a series of pairs of rollers 13 a, 13 b, 13 c,13 d. Each roller of one pair is shaped in accordance with thedeformation print to be created on one side of the conductor. The printis created by engaging the roller on the side with a certainpredetermined pressure. Engagement occurs in a direction transversal tothe axis 100′ of the feeding path.

The rollers of one pair 13 a, 13 b, 13 c, 13 d rotate with respect toeach other in a synchronous and opposite manner. Moreover, the rotationof the rollers can be synchronized with the rotation of the belts 16 aand 16 b through the controller 15.

The transversal pressure applied by the rollers deforms thecross-section of the conductor 10, from circular to rectangular in thecase shown in FIG. 1.

More specifically, the roller pairs 13 a, 13 b, 13 c, 13 d are mutuallyarranged at 90°, so that their profiles are oriented according to asuccession of deformations in the following order: the conductor's sidesare deformed for a first time by the pair 13 a; then the conductor's topand bottom are deformed for a first time by the pair 13 b; subsequentlythe conductor's sides are deformed for a second time by the pair 13 c;finally, the conductor's top and bottom are deformed for a second timeby the pair 13 d.

The unit 14 downstream of the unit 13 along the feeding path is capableof providing information useful for measuring the conductor length beingfed from the moment when a conductor's cut end passes by the photocell17 positioned after the unit 14. In fact, the photocell 17 can signalthe presence of a cut end of the conductor 10, and can therefore startthe counting of the length of the conductor being fed to the bendingunit 18. The counting is done by the control system 15, which uses thelength passage information transmitted by the measurement wheels in theunit 14 and the count start signal transmitted by the photocell 17.

The bending unit 18 is capable of bending the conductor in order to haveit take the desired coil member configuration, e.g. the coil membersshown in FIGS. 2 and 7. FIG. 2 shows a hairpin 250 with legs 130 and130′ that will have to be inserted into the slots of a core. FIG. 7shows an undulated coil 230 that typically constitutes one phase of thecore of an dynamo electric machine. The legs 220 of the coil areinserted into the slots of the core, while the heads 240 remain adjacentto the core ends. Each portion 230′ and 230″ consisting of two legs andone head may have a configuration similar to a hairpin like the oneshown in FIG. 2.

FIG. 4 shows the directions 5-5 and 5′-5′ according to which thecross-sections are viewed, respectively A and B in FIG. 5,demarcated/separated by the reference line C in FIG. 5.

With reference to FIGS. 4 and 5, the bending unit 18 comprises a supportmember 20, which is cylindrical in shape and includes a centralperforated part. The support member 20 is mounted on the bearings 20′ ofthe frame 30 of the bending unit 18, so that the central perforated partis coaxial to the axis AC′ of the conductor 10.

The feeding axis AC′ is a theoretical reference that can be consideredto coincide with the axis of the feeding path 100′ of the conductor 10,as shown in FIGS. 1, 3, 4 and 5.

The crown gear 31 is mounted integral with one end of the support member20, as shown in FIG. 5. The crown gear 31 is turned by the rotations Ror R′ (see FIG. 4) around the axis AC′ by the motor/pinion assembly 500schematically shown in FIG. 4, and partly also in FIG. 3. As a result,the support member 20 is also turned by the rotations R or R′ around theaxis AC′.

With reference to FIG. 5, the support member 20 supports the shaft 29 inan eccentric manner on the bearings 29″. The shaft 29 carries at one enda screw portion 29′ and at the other end a toothed wheel 34′ (see alsoFIG. 4). The toothed wheel 34′ meshes with the inner toothing of thecrown gear 34 (FIG. 5). The crown gear 34 is mounted on the bearings 34″to be coaxial to the axis AC′. When the crown gear 34 is rotated throughthe motor/pinion 200 (see FIGS. 3 and 4), the shaft 29 rotates on thebearings 29″ of the support member 20, thus turning the screw portion29′, which is screwed in a threaded sleeve 70 mounted integral with aslide member 22.

The central perforated part of the support member 20 houses the tube 21.The slide bushings 21′ are interposed between the tube 21 and the slidemember 22. In this way, the slide member 22 is supported by the tube 21and can move on the bushes 21′ in the directions T or T′, i.e. parallelto the axis AC′ and to the axis 100′, with respect to the tube 21 whenthe screw portion 29′ is turned by the motor/pinion 200.

The tube 21 is secured to the frame 30 by means of the fastening plate25. As shown in FIGS. 1 and 5, the tube 21 passes through the centralperforated part of the support member 20 to be joined to the fasteningplate 25. The conductor 10 passes inside the tube 21 while being fed inthe direction 10′, and then comes out through an end nozzle 80 to reachthe conductor bending members, which will be described more in detailhereafter.

The bearings 21″ are mounted between the support member 20 and the tube21 to allow the rotations R and R′ of the support member 20 around theaxis AC′ with respect to the tube 21, which is secured to the frame 30through the plate 25.

A second slide member 23 is adapted to slide on the slide member 22 (seeFIGS. 1, 3, 4 and 5). More specifically, the second slide member 23 canmove in the directions X and X′ with respect to the slide element 22.The directions X and X′ may be transversal to the axis AC′, moreprecisely perpendicular to the axis AC′. The motion of the second slidemember 23 on the slide member 22 in the directions X and X′ is madepossible by the guides 39, which are arranged in directionsperpendicular to the axis AC′ and are mounted between the slide member22 and the second slide member 23.

The motion in the directions X and X′ takes place through the rotationof the gear 41, which meshes with the rack 37 secured to the secondslide member 23, as shown in FIG. 5. The gear 41 is secured to the endof the shaft 42, which is adapted to rotate on the slide member 22. Theshaft 42 receives the shaft 44 in a bore 42′ at its end, as shown inFIG. 5. There is a key connection (not shown) between the shaft 44 andthe bore 42′, which allows the slide member 22 to translate in thedirections T and T′ and transmits the necessary rotation to the shaft 42and hence to the gear 41. The support member 20 supports the extensionof the shaft 44 on the bearings 44′. The shaft 44 carries the toothedwheel 36 on its end adjacent to the plate 25. The toothed wheel 36meshes with the inner toothing of the crown gear 33. The crown gear 33is mounted on the bearings 33′ to be coaxial to the axis AC′. When thecrown gear 33 is rotated by the motor/pinion 400 (see FIGS. 3, 4 and 5),the shaft 44 turns on the bearings 44′ of the support member 30 and thusrotates the gear 41 to move the second slide member 23 in the directionsX and X′.

The member 38 is movable in the directions X and X′ on the second slidemember 23. The member 38 comprises a first rack portion 38′ and a secondrack portion 38″ (see FIGS. 3 and 5). The member 38 can move in thedirections X and X′ by sliding on the guide 40 of the second slidemember 23.

The motion of the member 38 in the directions X and X′ takes placethrough the rotation of the gear 45, which meshes with the rack portion38′. The gear 45 is fitted to the end of the shaft 65, which is adaptedto rotate on the slide element 22. The shaft 65 receives the shaft 66 ina bore 65′ at its end, as shown in FIG. 5. There is a key connection(not shown) between the shaft 66 and the bore 65′, which allows theslide element 22 to translate in the directions T and T′ while at thesame time transmitting the necessary rotation to the shaft 65, and henceto the gear 45. The support member 20 supports the shaft 66 on thebearings 66′. The shaft 66 carries on one end the toothed wheel 35. Thetoothed wheel 35 meshes with the inner toothing of the crown gear 32.The crown gear 32 is mounted on the bearings 32′ to be coaxial to theaxis AC′. When the crown wheel 32 is rotated by the motor/pinion 300,the shaft 66 turns on the bearings 66′ of the support member 20 and thusrotates the gear 45 to move the member 38 in the directions X and X′.

The conductor bending tool 50 (see FIGS. 3,4,5 and 6) comprises at leastone of the pins 51 and 52 integral with the base 53.

As shown in FIGS. 3, 5 and 6, the pins 51 and 52 are spaced out along astraight line passing through the centre of the base 53. The base 53 issecured by means of screws (not shown) to the upper part 54″ of theshaft 54, so that its centre is centred on the axis 54′ of the shaft 54(FIG. 6).

The shaft 54 is slideable in the directions Z and Z′ in the centralperforated part of the member 56, which is integral with the secondslide member 23, and is therefore slideable in the directions Z and Z′with respect to the second slide member 23. The directions Z and Z′ areperpendicular to the axis AC′, as shown in FIGS. 3, 4 and 6.

The member 56 is supported on the bearings 55 mounted in the supportbell 57 (see FIG. 6). The support bell 57 is secured to the second slidemember 23 through screws 58. Around the circumference of the member 56there is a toothing 56′ which is concentric to the axis 54′. Thetoothing 56′ meshes with the toothing of the second rack portion 38″ ofthe member 38. The meshing of the toothing of 38″ is made possible by acutout in the support bell 57, which allows the member 38 to approachthe member 56, as shown in FIG. 6.

The movements of the member 38 on the second slide member 23 in thedirections X and X′ as described above cause the shaft 54 to rotate,bringing along the pins 51 and 52 of the rotation RO, or of the oppositerotation RO′, on the second slide member 23, i.e. around an axis RZ (seeFIGS. 4 and 6).

In fact, the key 60 on the shaft 54 engages a seat 60′ in the centralperforated part of the member 56. The seat 60′ is parallel to the axis54′. Therefore, rotation is transmitted from the member 56 to the shaft54, and the shaft 54 is allowed to slide parallel to the axis RZ.

The axis RZ can be considered to be a reference axis perpendicular tothe axis AC′. The axis of the shaft 54′ is parallel to the axis RZ andcan be considered to coincide with the axis 54′, as shown in FIG. 6.

The drive cylinder 61 is secured to the surface 23′, as shown in FIGS.3, 5 and 6. The rod 61′ of the cylinder 61 is coupled to the arm 62, asshown in FIG. 6. The shaft 54 is also coupled to the arm 62, as shown inFIG. 6.

When the cylinder 61 is actuated, the shaft 54 is therefore moved in thedirections Z and Z′, parallel to the axis RZ, and as a result also thepins 51 and 52 can move in the directions Z and Z′, parallel to the axisRZ.

The movements of the member 38 on the second slide member 23 in thedirections X and X′ cause the shaft 54 to rotate, bringing along thepins 51 and 52 on the second slide member 23, around the axis RZ on thesecond slide member 23. Therefore, the pins 51 and 52 are supported onthe second slide member 23 to rotate around the axis RZ of the rotationsRO and RO′.

The possible movements of the pins 51 and 52 are summarized in FIG. 4,with particular reference to the axis RZ previously defined asperpendicular to the axis AC′, which is integral with the second slidemember 23 between the pins 51 and 52.

Through movements T and T′ of the slide member 22 generated by themotor/pinion 200, the axis RZ translates perpendicular to the planecontaining FIG. 4. With the movement T the axis RZ translates towardsthe observer of FIG. 4, whereas with the movement T′ the axis RZtranslates away from the observer of FIG. 4. Both movements are parallelto the axis AC′. Consequently, the same translation movements are madeby the pins 51 and 52.

Through the movements of the second slide member 23 in the directions Xand X′ with respect to the slide member 22, generated by themotor/pinion 400, the axis RZ translates transversally to the axis AC′.Consequently, the same translation movement is made by the pins 51 and52.

Through the rotations of the support member 20 around the feeding axis100′, generated by the motor/pinion 500, the axis RZ rotates around theaxis AC′ of the opposite rotations R or R′, in that the surface 23′rotates in the same manner around the axis AC′. Consequently, the samerotational movement R or R′ is made by the pins 51 and 52.

Through the actuation of the cylinder 61, the pins 51 and 52 are movedperpendicularly towards or away from the axis AC′. In this case, thepins 51 and 52 translate parallel to the axis RZ.

Through the movement of the member 38 on the second slide member 23 inthe directions X and X′, generated by the motor/pinion 300, the pins 51and 52 perform rotations RO or RO′ around the axis RZ.

FIG. 3 shows the cutting assembly 101 assembled on the tube 21 upstreamof the nozzle 80. The assembly 101 comprises two cutting blades TG (seeFIGS. 8-13), each positioned on a respective side transversal to theconductor 10. A drive device included in the assembly 101 can move bothblades TG simultaneously in the direction TG′ (see FIG. 8), i.e.transversally to the conductor 10, in order to cut the conductor at apredetermined length defined by the length measurement reference 17 usedby the controller 15, thus allowing to release a coil member formed inthe bending unit 18.

For clarity and simplicity, in FIG. 5 the assembly 101 has been omitted.

FIGS. 8-13 show some bending operations which can be carried out byimplementing the methods and the apparatus of the invention.

With reference to FIGS. 8 and 8 a, the pins 51 and 52 are initially inthe idle position, indicated by a dashed line. They are therefore on oneside of the conductor 10, both aligned with an axis parallel to the axisAC′.

To reach this position, the pins have been rotated by the rotations ROor RO′ around the axis RZ, translated in the direction X′, and rotatedaround the axis AC′ by a rotation R with respect to the position of FIG.4.

The bending of FIGS. 8 and 8 a creates a gentle curve in the conductor10 starting from the contact CC at the outlet of the nozzle 80 of thetube 21. Bending and contact are obtained as the pins 51 and 52 move tothe position where the pins are drawn with a continuous line.

This bending movement of the pins 51 and 52 is obtained by using acombination of rotation RO around the axis RZ and movement of the pins51 and 52 in the direction X. During these movements, the pins apply atransversal force onto the conductor 10 in order to bend it as indicatedby the continuous line of the conductor 10 in FIGS. 8 and 8 a.

The bending shown in FIGS. 9 and 9 a can start from a position of thepins 51 and 52 initially similar to the idle position of FIG. 8, thepins 51 and 52 being however closer to the nozzle 80 and hencetranslated less in the direction T. FIG. 9 shows a sharper curve of theconductor 10, obtained by bending it starting from the contact CC at theoutlet of the nozzle 80 as the pins 51 and 52 move to the position drawnwith a continuous line. This movement of the pins 51 and 52 is obtainedby using a combination of a greater rotation RO (compared to FIG. 8) anda greater movement in the direction X (compared to FIG. 8) of the pins51 and 52.

The bending of FIGS. 10 and 10 a occurs in a different plane, e.g. theplane of the view B of FIG. 5, wherein a gentle curve is created in theconductor 10, like the one shown in FIG. 8. The pins 51 and 52 areinitially in the idle position, drawn with a dashed line, i.e. on oneside of the conductor and both aligned with an axis parallel to the axisAC′. The movements of the pins 51 and 52 required to obtain this bendare similar to those of FIGS. 8 and 8 a, i.e. translation in thedirections X and rotation RO around the axis RZ, but they take place indifferent planes, as allowed by the rotation R of the support member 20(see FIG. 10a ).

The bending of FIGS. 11 and 11 a produces in the conductor 10 a curvethat practically follows the geometry of an arc of a circle. This bendis obtained by feeding the conductor 10 to first cause it to engage thepin 51, where it is deviated, and then by keeping feeding it to cause itto engage the pin 52 positioned as shown in FIGS. 11 and 11 a. Thisresults in a bend created through contact at CC, pressure against thepin 51 and pressure against the pin 52, as shown in FIGS. 11 and 11 a.

In summary, the pins 51 and 52 have been translated in the direction T′,translated in the direction X, rotated by the rotation RO around theaxis RZ, and rotated by the rotation R around the axis AC′.

The bending shown in FIGS. 12 and 12 a produces a very local curve inthe conductor 10. The conductor 10 is positioned between the pins 51 and52, after these have been translated in the direction Z parallel to theaxis RZ to be positioned on each side of the conductor (FIGS. 12, 12 a).Afterwards the pins 51 and 52 have been rotated by the rotation ROaround the axis RZ to obtain the very local curve.

The torsion bending of FIGS. 13, 13 a requires the pins to approach eachother to grip the conductor. In order to provide this gripping action onthe conductor 10, a mechanism is added to the solution of FIG. 5. Oncethe conductor has been gripped, the rotation R around the axis AC′exerts a torsion TR on the conductor as shown in FIG. 13. Thecounteraction necessary to create the torsion TR is given by theengagement of the conductor 10 with the walls of the nozzle 80.

The coil member of FIG. 2 corresponds to a hairpin manufactured with arectangular cross-section by the apparatus of FIG. 1 by starting from acircular cross-section conductor stored in the magazine 11. The unit 13then transforms the conductor's cross-section from circular torectangular.

The bending unit 18 creates the bend that characterizes the hairpins ofFIG. 2 and cuts the ends of the legs 130 and 130′. In fact, thecontroller 15 will have been programmed to carry out steps like thosedescribed in FIGS. 8-13 in order to create in succession the bendportions making up the hairpin and to cut the conductor by means of theunit 101.

For the hairpin of FIG. 2, the succession of bending steps may be asfollows: in a first step the straight portion of the leg 130 is fedthrough the nozzle 80. This first step follows the cutting of the end ofthe leg 130 that took place at the end of the bending of a previoushairpin, or after the initial cutting of a conductor 10 which wasreplaced in the magazine 11.

In a second step the bend portion 131 is made, which consists of a curveand a torsion obtained, for example, by applying the principles of FIG.9 and FIG. 13, respectively.

In a third step the bend portion 132 is made, which consists of agentler curve obtained, for example, by applying the principles of FIG.8.

In a fourth step the bend portion 133 is made, which consists of a curveand a torsion obtained, for example, by applying the principles of FIG.9 and FIG. 13.

The other portions 134, 135, 136 and 130′ that complete the hairpin aremade in a similar manner through an appropriate combination of thebending operations of FIGS. 8-13 obtained by programming the controller15 accordingly.

Finally, a robot's manipulator (not shown) may grasp the hairpin toremove the end portion of the leg 130′ from the nozzle 80 after thecutting operation has been performed by the unit 101.

As regards the coil member of FIG. 7, the portions 230, 230′, 230″ ofthe coil 230, which have a configuration similar to the hairpin of FIG.2, can be formed in succession by the unit 18 through a series ofbending operations carried out through an appropriate combination of thebending operations of FIGS. 8-13, again obtained by programming thecontroller 15 accordingly.

In one embodiment of the present invention, the bending tool 50comprises only one pin 51 or 52 for performing the bending operationsdescribed with reference to FIGS. 8-10.

Furthermore, simpler coil configurations may only require a bendingobtained through the movement of at least one of the pins 51 and 52 inthe direction X and X′; in this case, the solution will be limited tothe transmission from the motor 400, i.e. crown gear 33, gear 36, shaft44, gear 41, rack 37 and guide 39 for the member 23, whereas the members22 and 23 will be integral with each other without having to mutuallyrotate or translate.

Other coil configurations may require the addition of the rotation R andR′ of the support 20 through the motor 500 and the crown gear 31.

Further configurations may require the addition of the translation T andT′ of the member 22 through the motor 200 and the screw portion 29′.

The above description of one specific embodiment has illustrated theinvention from a conceptual viewpoint, so that others, by usingprior-art techniques, will be able to modify and/or adapt said specificembodiment to various applications without further research and withoutdeparting from the inventive concept. It is therefore understood thatany such modifications and adaptations will be considered to beequivalent to the exemplary embodiment described herein. The means andmaterials necessary for implementing the various functions describedherein may vary without departing from the scope of the invention. It isunderstood that the expressions and terminology used herein are merelydescriptive and hence non-limiting.

The invention claimed is:
 1. An apparatus for manufacturing coil membersfor insertion in slots of a core of a dynamo electric machine whereinthe coil members are formed by bending portions of an electricconductor, the apparatus comprising: means for feeding portions of theelectric conductor of predetermined length through an aperture, along afeeding axis, according to a feeding direction, adjacent to a firstengagement member capable of engaging the electric conductor, whereinthe aperture is positioned before the first engagement member in thefeeding direction; means for moving the first engagement member withrespect to the aperture to engage a portion of the electric conductorwith the first engagement member in a transverse direction to thefeeding axis to bend the electric conductor; and means for rotating thefirst engagement member around the feeding axis to reposition the firstengagement member around the electric conductor.
 2. The apparatus ofclaim 1, wherein the means for moving the first engagement member movethe first engagement member for engaging the electric conductor againsta portion of the aperture during bending.
 3. The apparatus of claim 1,further comprising means for moving the first engagement member parallelto the feeding axis to position the first engagement member for bending.4. The apparatus of claim 3, further comprising a first support assemblyrotated around the feeding axis, a second support assembly capable oftranslating transversally to the feeding axis; the first engagementmember being supported by the second support assembly.
 5. The apparatusof claim 4, further comprising a member for passage of the electricconductor on a path to reach the first engagement member; whereinrotation of the first support assembly is around the member for passageof the electric conductor; and wherein translation of the second supportassembly is supported by the member for passage of the electricconductor.
 6. The apparatus of claim 3, further comprising a firstsupport assembly rotated around the feeding axis, a second supportassembly capable of translating parallel to the feeding axis; and athird support assembly supported by the second support assembly; thefirst engagement member being supported by the third support assembly.7. The apparatus of claim 3, wherein means for moving the firstengagement member parallel to the feeding axis comprises a crown gearrotated around the feeding axis.
 8. The apparatus of claim 1, furthercomprising means for rotating the first engagement member around an axisthat is perpendicular to the feeding axis.
 9. The apparatus of claim 8,further comprising means for moving the first engagement member parallelto the axis that is perpendicular to the feeding axis.
 10. The apparatusof claim 8, wherein the means for rotating the first engagement memberaround an axis that is perpendicular to the feeding axis comprises acrown gear rotated around the feeding axis.
 11. The apparatus of claim1, wherein the means for feeding feed the electric conductor adjacent toa second engagement member capable of engaging the electric conductor;the second engagement member is positioned after the first engagementmember in the feeding direction; and the second engagement member iscapable of engaging the electric conductor transversally with respect tothe feeding axis.
 12. The apparatus of claim 11, further comprisingmeans for rotating the first engagement member and the second engagementmember around a rotation axis to engage the electric conductor with thefirst engagement member and the second engagement member transversallywith respect to the feeding axis.
 13. The apparatus of claim 1, whereinthe first engagement member and a second engagement member grip theelectric conductor; and further comprising means for rotating the firstengagement member and the second engagement member around the feedingaxis to apply torsion to the electric conductor.
 14. The apparatus ofclaim 1, wherein the means for moving the first engagement member withrespect to the aperture comprises a crown gear rotated around thefeeding axis.